Friction facing



' Marsh 10, 1925. 1,528,929

H. F. KNECHT ET AL FRICTION FACING Filed April 30, 1924 ALFRED E (ARPENTER HOWARD E mac/1r IN VEN TORS BY M EPA/{$57 A TTORNE Y Patented Mar. 10, 1925.

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" 1. ERIe'rIo-N FACING.

.e ncationrmeaepril 30, 1924..- SeriaLNo. 710929...

To, all whom itmayoonoeom;

Be it known that we, HOWARDF. K NEGHfl. and ALFRED i (Linnrznirra,V citizens .of; .i the United States and residing at Cleveland, in; the county of'Guyah gaI-and.Statxot Ohio, have' invented new and useful Im.- provements in Friction Faoings, ofwhich the following is a specification.

This invention relates to a friction facing for; friction surfaces such as are commonly employedin clutches, transmissions, brakes, etcL, and ji'n particular where such. devices operatein .a bath orispray of oil suchaas is commonpraetiee 2i1 1.=;the planetary types of. automobile transmission and' the transmission ,type. of automobile brake.

According tothe1present practice a fric-v tion facing in the form of a lining consist: ing of'astrip of friction, fabric isYsecu-red to the inner face of a flexible brake band whichyis adapted to be. tightened-about a revolving drumftherebyapplying a desired degree; of friction so as .to gently checlizthe speed ofthe drum or holdit against 1 0-. tation. Such braking arrangement is com: monly. housed within a, suitable casinglco'ntaining enough 'oil'to normally'cover the lower part; of'the revolving. mechanism,

whiclrwhem in motion so agitates. the oil that ,fOI' PIRICtlGaI 1111331 0308 all-parts of {the mechanism are surrounded -.by an ;oil ispray. Lubrication of; the friction, surfaces when. braking must be obtained from either-re.- sidual ;oil in the brake band lining. of. friction fabric, or in oil which ,each successive portion of the revolving ci TCM -mfEBenc-e. of the: drum obtainsdijiringthat part. of -its cyclewhich carries it;beneath the leyekof the oil in the casing-. But "inorderthat thlelining may possess. the requisitetensile strength, wearing quality, heat and oil resistance, etc.,' it is." expedient that the fabric, be pre treated-f by; impregnation with a filling element and also by being subjected to a high compression. Obviously the result of each of these, treatments, whose object is to increase the density, is to decrease porosity. Moreover when the brake is applied with the most force, and lubrication is most needed, there is the least opportunity for oil to reach the friction surfaces from an outside source because they are then in the closest engagement.

For these reasons as well as others the .iil within the reservoir is not able to funct s t t e t i fii n sur a es n a at s a tory mannerespecially whenthe brake must be applied vwith great force. or for, long, intervals,, and the result: is. that the friction surface of, thebrake lining soon becomes glazed andfihardened,and due to excessive Wear is Very short lived."

The. object. of the present invention is to both lengthen, the life .of:tl1e friction material and-insurea smooth engagement of the friction surfaces by. providing. adequate and? thorough lubrication. to them at all times.

InQthe embodiment of this invention, illus trated:

Figs. 1. and 2 are perspective views respeetivelyof alubricating plug, and a section of 5 friction,material'perforated to receive the plug.

Fig. 3-is alongitudiznal sectional View of thefpart shown in Fig. 2 Withthe plug of I inserted therein.

. Fig. 4:18 a Iview. similar to that of Fig. 3 shioiving the friction material or. lining secured to itsbacking.

Fig. 5 is a View partly insection showing the.li:ning as. applied to abr'ake band as usediin an'ordinar'y planetary automobile transmission.

Fig. 6 isan optionalform of lubricating plug,- 1. i

A preferred manner of constructing a sectlODfi-lflllllbOfOlll. invention is as follows: A.plug, 1, preferably cylindrical, as in Fig. 1,01. of other-shape, forexample conical as,in Fig. 6,.of felt. or other porous material is. forced'into a verytig'htly fitting correspondingly shaped: perforation in the friction material, 2, in such mannerthat onejendofithe plug is flush with the friction surface. A, ofthe friction material, while the other end ofthe plug is left protruding from the; opposite or innerlside ofwthe frict'ion material-Tin. much the same. manner as an ordinary rivet would be secured. We have preferred to illustrate as an example an ordinary brake band lining such as is used in a planetary automobile transmission. In. this case a number of such plugs are inserted at intervals along the center of the strip of friction material with which the brake band is lined. The lining is next secured to the brake band, 3, as shown in Fig. 4, in the ordinary manner by means of rivets, 4, passing through both the brake band, 3, and the brake lining, 2. It will be noticed that owing the protrusion of the head of the plug, 1, beyond the rear, surface of the lining, 2, a circular space, 5, is provided between the brake band and the lining. As shown in Fig. 5, an area of spacing, 5, between the brake band and lining is thus provided at each plug and extends to the lateral edges of the brake.

The manner of operation is as follows: As shown in Fig. 5 and described above, the lower part of the entire mechanism is submerged in oil to the approximate level of the line B, and rotation of the drum, 6, causes this oil to be so agitated that the whole surface of the mechanism is continually wet. hen the brake is loose upon the drum sufficient oil is carried around by the face of the drum so that the friction surfaces are always wet. When the brake is applied, however, there is little or no opportnnity for more oil to reach the friction surfaces which, because of the heat generated by the braking friction very quickly require additional oil for smooth action.

By reason of the plugs, 1, however, and their protruding heads, when the brake is first applied the pressure of the brake band upon the heads causes the plugs to give up their oil to the friction surface in the same manner as sponges being squeezed. And with continued application of the brake, owing to the spaces, 5, there is always opportunity for oil to reach the heads of the plugs. The plugs in turn being of porous material feed this oil to the friction surfaces by capillary attraction as wicks and this action continues as long as the brake is applied. It is not necessary that the spaces, 5, be as great as is shown in Figs. 4 and 5 which have been exaggerated in order to illustrate the principle of action.

While only one form of our invention is herein set forth in detail, we intend the invention, as disclosed in Figs. 1 to 4, to be comprehensive of application in conjunction with any friction material. to any shape of friction surface, such as plane, cylindrical or conical, and with any arrangement of the lubricating plugs in the friction material.

Having thus described and illustrated our invention, what we claim is:

1. A friction facing of the character described comprising a friction material and spacing projections extending beyond the back surface of said friction material.

2. A friction facing of the character described comprising a friction material and a plurality of porous spacing projections extending beyond the back surface of said friction material.

3. A friction facing of the character described comprising a friction material, a plurality of porous inserts therein, and spacing projections extending beyond the back surface of said friction material.

4. A friction facing of the character described comprising a friction material and a plurality of porous inserts therein protruding at the back of said friction material.

5. A friction facing of the character described comprising a friction materialand a plurality of porous inserts therein flush with the friction surface of said friction material and protruding beyond the op posite surface of said friction material.

6. A friction facing of the character described comprising a friction material and a plurality of porous inserts therein adapted to absorb a lubricating fluid and to release said fluid under pressure from the back. 7

7. A friction facing of the character described comprising a friction material, spacing means upon the back surface of said friction material, and capillary connection between said back surface and the friction surface of said friction material.

8. A friction facing of the character described comprising a friction material, porous spacing means upon the back surface of said friction material, and capillary connection between the said back surface and the friction surface of said friction material.

9. A friction facing of the character described comprising a friction material, porous spacing means upon the back surface of said material, and extending through the said material to the friction surface of said material.

Signed by us, this 26th day of April,

HOWARD F. KNECHT. ALFRED F. CARPENTER. 

